Speedometer Plastic Gears, Need one (Help).

Hello

I have a 1986 Mercedes 560SL Roadster, the top small gear on the speedometer
just broke. It shows the speed limit you are going but the mileage hands stopped turning.
I was wondering if anyone know where to get the plastics gears so I can replace them.
This unit is electronic by the way, not cable driven.

Thanks,